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Missing Values

Frank Puzycki
in CCDStack
I am trying to use CCD Stack's missing values feature to tamp down M42's Trapizium bloat in my 3 minute sub exposures.  I take 3 second exposures with my OSC color SBIG imager.  By Adam's tutorial on this same target, in normalizing the 3 minute to the 3 second expsoures I should get a weighted value of 0.0167 for the 3 second subs.  Instead I am getting values of 0.442 and similar numbers selecting the same dark and light regions he uses in the tutorial.  Any thoughts - my only guess is tthat the dark/light areas I highlight are somehow not correct.  I am operating on subs that are first calibrated and then are split into RGB and Lum sets of files for booth exposure times.


Frank Puzycki

Comments

  • BlockHeadBlockHead
    Many OSC are 12-bit sensors. Could this be a source of difficulty?

    -the Blockhead
  • Frank Puzycki
    No because I went back to a Sept imaging session of M31, did the same precise process and got the exact weighting factor for a 15 second exposure that should have occurred.  As stated in the video, the universe works as it should!  I am going to trash all of the M42 processing I did recently and start from scratch using the CCDSTK process recommended.  BTW, I am also seeing weird black, grey and white pixelated textures in the missing value area I defined (>40000 and <than 100000) in the replaced missing values steps in the video's process.  I was out last night to shoot M78 and resisted the temptation to shoot M42 again but I plan on doing so after full moon.  Any other thoughts or does the above cited pixelated observation suggest something else I am doing wrong?
  • BlockHeadBlockHead
    Without seeing a screenshot I cannot say. However, I think I was much more conservative by using <35000 or something along those lines.

    -the Blockhead
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